Structural and magnetic properties of Li3RuO4

Abstract

The crystal structure of Li₃RuO₄ has been refined from neutron powder diffraction data collected at 290 K (space group P2/a, a = 5.1057(1), b = 5.8545(1), c = 5.1062(1) Å, β = 110.039(1) °) and 5 K. It can be thought of as an ordered rock-salt structure with chains of edge-sharing RuO₆ octahedra embedded in a matrix of LiO₆ octahedra. Comparison of the structure with that predicted by computational chemistry shows that the calculations model well all but the Li sublattice. Consideration of ⁶Li NMR spectra and the diffraction data shows that some (∼1%) sites on the Li sublattice are occupied by Ru. SQUID magnetometry shows a non-hysteretic maximum in the magnetic susceptibility of Li₃RuO₄ at 50 K, but no long-range magnetic order is apparent at 5 K. The susceptibility maximum is therefore attributed to antiferromagnetic coupling within individual chains of RuO₆ octahedra.